We’re always complaining about the sticky weather in Singapore, especially the recent heat wave we’ve been experiencing – and now it seems it’s possibly affecting more than our moods.

A working paper from the National Bureau of Economic Research analysed data from all over the USA and found fewer babies are born eight to 10 months after the temperature rises above 26.6° C.

But Singapore’s average daily temperature is fairly often above this figure, especially in May and June, when our average daily temperature hovers around 27.7 °C.

The US researchers noted that each day above 26.6 °C from 1931 to 2010 led to 1,165 fewer births, on average in the USA. And the dip continued afterwards: the birth rate only bounced back 32 percent in the 13 months following each heat wave. The researchers studied all this as part of on-going research into how global-warming may affect population growth around the world.

Hot and bothered

It’s true that sex doesn’t seem that appealing when you’ve already feeling hot, sticky and tired. After a day trudging around in Singapore’s steamy heat you’re maybe more keen for a cool shower than a hot date.

Cooling down may help: the report notes that the US birth rate re-bounded by a third in the 70’s, right about when home air conditioning units started to become common.

Or in science-speak: “We document a significant dampening in the temperature-fertility response function beginning in the 1970s and show that residential access to air conditioning explains about one third of this dampening,”

Basically it means that if you’re keen to start a family – or just have a better love life – your best sex aids may be a great air conditioner or an efficient ceiling fan.

But don’t let this info cool your excitement too much if you’re already planning on having kids. This is just one study and it’s just in the US. Maybe it’s only relevant to countries that have defined hot and cold seasons? No-one knows yet.

It’s also worth noting that out of the 10 youngest nations by population in the world, eight of them are in Africa. And last we heard, it’s pretty warm there.